The present invention relates to a pin electronic adapted for usage in an automatic test equipment for testing integrated circuits.
Automatic test equipment (ATE) is used for testing electronic components such as integrated circuits (ICs). An IC ATE usually comprises several channels associated with respective pins of a device under test (DUT). A channel includes a pin electronic for generating and measuring signals at the associated pin of the DUT. For the signal generation, each pin electronic comprises a driver circuit capable of generating a digital data stream as determined by a testprocessor connected to the pin electronic. Several channels are usually combined in a so-called channel module which may be mounted on a heat sink or cooled by air in order take away the heat due to the power consumption. Each channel module is connected over an interface circuit for enabling a communication between one or more testprocessors and a computer controlling the ATE.
For performing various measurements of parameters of the DUT such as the input leakage current of an input pin of the DUT, the ATE can also include one or more parametric measurement units (PMU). During a parametric measurement, the pin electronic is switched into a measurement or PMU mode. In the PMU mode, the driver circuit of the pin electronic is disabled and disconnected from the testing input pin of the DUT. Then, the PMU is switched on and connected with the testing input pin, for putting a constant voltage at it or driving a constant current. The PMU measures the current flowing into the testing input pin driven by the constant voltage, or the voltage at the input pin generated by the constant current. The measured current or voltage, respectively, is a parameter for the input leakage or voltage stability of the testing input pin. Parametric measurements require a high degree in accuracy of the voltage or current at an input pin of the DUT. Therefore, each PMU is supplied by an electric power supply separated from the power supply for the driver circuit for generating substantially constant voltages and currents.